Charlotte invested $100 per year into a business for 3 years. The total value of her investment after 3 years is represented by the algebraic expression below, where x is the growth in value
each year.
100 (x3 + x2 + x)
What is the total value of her investment when x = 2?
$1200
$1400
$600
$6400

Here is their argument. given the obtuse angle x, we make a quadrilateral abcd with ∠dab = x, and ∠abc = 90◦, and ad = bc. say the perpendicular bisector to dc meets the perpendicular bisector to ab at p. then pa = pb and pc = pd. so the triangles pad and pbc have equal sides and are congruent. thus ∠pad = ∠pbc. but pab is isosceles, hence ∠pab = ∠pba. subtracting, gives x = ∠pad−∠pab = ∠pbc −∠pba = 90◦. this is a preposterous conclusion – just where is the mistake in the "proof" and why does the argument break down there?

What are the constants in this expression? -10.6+9/10+2/5m-2.4n+3m

Brent wants to know what is 5 x 1/2